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Role of flavin-containing monooxygenase in oxidative metabolism of voriconazole by human liver microsomes.

Publication ,  Journal Article
Yanni, SB; Annaert, PP; Augustijns, P; Bridges, A; Gao, Y; Benjamin, DK; Thakker, DR
Published in: Drug Metab Dispos
June 2008

Voriconazole is a potent second-generation triazole antifungal agent with broad-spectrum activity against clinically important fungi. It is cleared predominantly via metabolism in all species tested including humans. N-Oxidation of the fluoropyrimidine ring, its hydroxylation, and hydroxylation of the adjacent methyl group are the known pathways of voriconazole oxidative metabolism, with the N-oxide being the major circulating metabolite in human. In vitro studies have shown that CYP2C19, CYP3A4, and to a lesser extent CYP2C9 contribute to the oxidative metabolism of voriconazole. When cytochrome P450 (P450)-specific inhibitors and antibodies were used to evaluate the oxidative metabolism of voriconazole by human liver microsomes, the results suggested that P450-mediated metabolism accounted for approximately 75% of the total oxidative metabolism. The studies presented here provide evidence that the remaining approximately 25% of the metabolic transformations are catalyzed by flavin-containing monooxygenase (FMO). This conclusion was based on the evidence that the NADPH-dependent metabolism of voriconazole was sensitive to heat (45 degrees C for 5 min), a condition known to selectively inactivate FMO without affecting P450 activity. The role of FMO in the metabolic formation of voriconazole N-oxide was confirmed by the use of recombinant FMO enzymes. Kinetic analysis of voriconazole metabolism by FMO1 and FMO3 yielded K(m) values of 3.0 and 3.4 mM and V(max) values of 0.025 and 0.044 pmol/min/pmol, respectively. FMO5 did not metabolize voriconazole effectively. This is the first report of the role of FMO in the oxidative metabolism of voriconazole.

Duke Scholars

Published In

Drug Metab Dispos

DOI

EISSN

1521-009X

Publication Date

June 2008

Volume

36

Issue

6

Start / End Page

1119 / 1125

Location

United States

Related Subject Headings

  • Voriconazole
  • Triazoles
  • Recombinant Proteins
  • Pyrimidines
  • Pharmacology & Pharmacy
  • Oxygenases
  • Oxidation-Reduction
  • Microsomes, Liver
  • Humans
  • Cytochrome P-450 Enzyme Inhibitors
 

Citation

APA
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MLA
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Yanni, S. B., Annaert, P. P., Augustijns, P., Bridges, A., Gao, Y., Benjamin, D. K., & Thakker, D. R. (2008). Role of flavin-containing monooxygenase in oxidative metabolism of voriconazole by human liver microsomes. Drug Metab Dispos, 36(6), 1119–1125. https://doi.org/10.1124/dmd.107.019646
Yanni, Souzan B., Pieter P. Annaert, Patrick Augustijns, Arlene Bridges, Yan Gao, Daniel K. Benjamin, and Dhiren R. Thakker. “Role of flavin-containing monooxygenase in oxidative metabolism of voriconazole by human liver microsomes.Drug Metab Dispos 36, no. 6 (June 2008): 1119–25. https://doi.org/10.1124/dmd.107.019646.
Yanni SB, Annaert PP, Augustijns P, Bridges A, Gao Y, Benjamin DK, et al. Role of flavin-containing monooxygenase in oxidative metabolism of voriconazole by human liver microsomes. Drug Metab Dispos. 2008 Jun;36(6):1119–25.
Yanni, Souzan B., et al. “Role of flavin-containing monooxygenase in oxidative metabolism of voriconazole by human liver microsomes.Drug Metab Dispos, vol. 36, no. 6, June 2008, pp. 1119–25. Pubmed, doi:10.1124/dmd.107.019646.
Yanni SB, Annaert PP, Augustijns P, Bridges A, Gao Y, Benjamin DK, Thakker DR. Role of flavin-containing monooxygenase in oxidative metabolism of voriconazole by human liver microsomes. Drug Metab Dispos. 2008 Jun;36(6):1119–1125.
Journal cover image

Published In

Drug Metab Dispos

DOI

EISSN

1521-009X

Publication Date

June 2008

Volume

36

Issue

6

Start / End Page

1119 / 1125

Location

United States

Related Subject Headings

  • Voriconazole
  • Triazoles
  • Recombinant Proteins
  • Pyrimidines
  • Pharmacology & Pharmacy
  • Oxygenases
  • Oxidation-Reduction
  • Microsomes, Liver
  • Humans
  • Cytochrome P-450 Enzyme Inhibitors